1. Field of the Invention
The present invention relates to an RDS (radio data system) receiver and, more particularly, to a receiver adapted to achieve enhanced effects when used in a home radio set.
2. Description of the Prior Art
It is known that, according to FM broadcasting in Europe, RDS data is added to original audio signals.
Such RDS data is an aggregate of digital data relative to broadcasting stations and a program, inclusive of the following:
PI code . . . Program identification code representing a country's name, a program and so forth PA1 AF list . . . A frequency list of broadcasting stations transmitting the same program therefrom
The RDS data is encoded for error correction, and a subcarrier signal having a frequency of 57 kHz (triple of frequency 19 kHz of a stereo pilot signal) is balance-modulated by the encoded RDS data. Subsequently such modulated signal is added to a monaural signal or a stereo composite signal to be thereby frequency-multiplexed, and the multiplexed FM signal thus obtained is transmitted.
Therefore a specific broadcasting station or a specific program can be received by utilizing the PI code or the AF list included in the RDS data. (Cited reference: "Nikkei Electronics", Aug. 24, 1987)